In working on automobiles or other machinery it is necessary to remove pulleys from their shafts. Up to the development of the present invention there were no tools available to imobolize a pulley by clamping an intact belt around the pulley. The techniques for removing a pulley required disassembling the peripheral parts surrounding the pulley so that a vise or the like could be applied to the pulley to secure it while the nut or bolt fastening the pulley to the shaft was removed.
The concept of an adjustable strap wrench is conventional. Greenawalt U.S. Pat. No. 4,987,804 describes a Strap Wrench including a housing having a top, a bottom, a first side, a second opposing side, an open front end and an open back end. A cam is mounted within the housing. The cam is disposed in the housing between the top of the housing and the bottom of the housing. The center portion of the cam is attached to the housing for pivotal movement therein such that the first end and the second end of the cam means are spaced apart from the respective sides of the housing. A section of a flexible belt that has been cut is threaded through the housing in the space between the cam and the first side of the housing forming a loop. The belt is locked between the cam and the housing to prevent movement of the belt. When the belt is so locked, the piece that the belt is wrapped around is stabilized. If this device is used to stabilize a pulley while installing or removing nuts or bolts that fasten the pulley to a shaft, a belt must be cut in order to be threaded through the housing of the device.
Other types of devices that hold belts or straps securely have been described in U.S. Pat. Nos. 3,465,622 issued to Winans, U.S. Pat. No. 4,114,481 issued to Kowalczyk and U.S. Pat. No. 4,506,568 issued to Aamodt. Both Winans and Kowalczyk disclose a clamping band with a center opening and the ends of the bands connected to pivot points. While being useful in removing oil filters, these devices have pivoting points which are subject to damage and further are substantially closed loops which can be used only with workpieces which are accessible from one end so that the loop can be slid over the workpiece. Aamodt discloses the ends of a strap passing through a longitudinal slot in each part of a two part cylindrical holder and overcomes the problems presented by Winans and Kowalczyk. However, the device of Aamodt comprises two separate holder pieces which must be placed one within the other. This is not easily accomplished in restricted work space. Further, loss or misplacement of one of the holder pieces renders the device useless.
U.S. Pat. No. 1,456,126 issued to Friday describes a strap wrench that is used primarily to loosen mason jar lids. It is composed of a handle, a jaw pivotally supported at one end of the handle. A flexible clamp is secured at one end to the jaw which is secured to the handle, which limits the pivotal movement of the jaw relatively to the handle, a post is attached on the handle which has an acentric cam providing an adjustable clamp for said flexible clamping member.
A chain wrench is disclosed in U.S. Pat. No. 2,353,642 issued to Buice. U.S. Pat. No. 4,160,394 issued to Crumpacker discloses a wrench having an elongated handle received on a bracket and a flexible loop connected to the handle. Adjustment means is provided by manipulation of a sleeve surrounding a rigid inner handle section. U.S. Pat. No. 3,373,637 issued to Behnke discloses a portable rotary drive unit having a rotary drive socket with a peripheral ring gear driven by a motor. These comparatively complex devices are expensive, relatively heavy, and are not conducive to work in confined spaces. U.S. Pat. No. 1,911,815 issued to Deringer et al disclose a strap wrench in which one end of the strap is attached to an elongated handle and the other end of the strap passes through several inclines and slots in the handle to secure the strap. Operation of this device is also restricted when working in a confined space. U.S. Pat. No. 3,962,936 issued to Lewis discloses a strap wrench having loose ends mounted in a cylinder having a slot passing diametrically through the center. The slot receives both ends of the strap and the cylinder is rotated, wrapping the strap around the cylinder to produce a tightening action.
U.S. Pat. No. 701,489 issued to Love discloses a pipe wrench wherein one end of the strap is attached to a handle, the strap passing through a slot in the handle, around the workpiece over a nose on the handle, and back through the same slot in the handle. U.S. Pat. No. 1,478,110 issued to Ellison also discloses a handle having a nose thereon over which the strap passes as the strap enwraps the workpiece. The handle further has two laterally extending arms and a bridge portion in which the strap is received. U.S. Pat. No. 2,186,430 issued to Richter discloses a household implement having a handle with a slot therein. One end of a strap is attached to the handle, the strap passing through the slot, around the workpiece and returning through the slot. U.S. Patent No. 2,458,393 issued to Loudfoot discloses a handle having three aligned openings and a frictional cord having both ends attached to the handle. The frictional cord is threaded through openings to form a loop to engage the workpiece. U.S. Pat. No. 2,995,965 issued to Hockney discloses a strap having one end folded about a pin and secured to the body of the strap. The other end of the strap is looped about the workpiece and threaded through an elongated slot in a cylindrical retainer body. The retainer body has ends which may engage a handle member to rotate the retainer body to secure the strap about the workpiece.
None of the prior art provides a belt clamp that can be used on a intact belt to stabilize a pulley while pulley bolts or nuts are loosened or tightened.